[en] In art analysis, copper phthalocyanine (CuPc) is often identified as an important pigment (PB15) in 20th century artworks. Raman spectroscopy is a very valuable technique for the detection of this pigment in paint systems. However, PB15 is used in different polymorphic forms and identification of the polymorph could retrieve information on the production process of the pigment at the moment. Raman spectroscopy, being a molecular spectroscopic method of analysis, is able to discriminate between poly- morphs of crystals. However, in the case of PB15, spectral interpretation is not straightforward, and Raman data treatment requires some improvements concerning the PB15 polymorphic discrimination in paints. Here, Raman spectroscopy is combined with chemometrical analysis in order to develop a procedure allowing us to identify the PB15 crystalline structure in painted layers and in artworks. The results obtained by Linear Discriminant Analysis (LDA), using intensity ratios as variables, demonstrate the ability of this procedure to predict the crystalline structure of a PB15 pigment in unknown paint samples.
Disciplines :
Arts & humanities: Multidisciplinary, general & others Physical, chemical, mathematical & earth Sciences: Multidisciplinary, general & others Chemistry
Author, co-author :
Defeyt, Catherine ; Université de Liège - ULiège > Centre européen en archéométrie
Van Pevenage, Jolien; Universiteit Gent - Ugent
Moens, Luc; Universiteit Gent - Ugent
Strivay, David ; Université de Liège - ULiège > Département de physique > Physique nucléaire, atomique et spectroscopie
Vandenabeele, Peter; Universiteit Gent - Ugent
Language :
English
Title :
Micro-Raman spectroscopy and chemometrical analysis for the distinction of copper phthalocyanine polymorphs in paint layers
Publication date :
2013
Journal title :
Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy